Students build strips of same-size base-10 unit blocks by sticking the blocks next to each other on tape, with instructions to make sure the blocks touch (Activity 5). Students count those unit blocks to make groups of lengths 1–5 and place unit blocks end-to-end to form strips. Students are asked to line the rods up to compare which strip is greater and to count how many more blocks one has than another, and to use unit blocks to show part-part-whole relationships up to 5 (Activity 4 and 5).

In Activity 4 students count out 10 unit (cube) blocks and are asked to line them up next to each other, touching them together to make a row, and then compare that row to a ten rod to see they are the same length. The directions explicitly prompt helping the child to line up the blocks so they "line up without any gaps." The "Showing 11-20" student page requires students to identify numbers from pictures of rods and unit cubes, reinforcing the practice of representing lengths as whole numbers of unit blocks.

Students count steps outdoors (e.g., asking how far they will go if they take 40 steps and then reviewing counting while taking steps to 40 and 50), which uses a repeated action (a step) to express distance as a whole number of units. Students cut shorter number strips and tape them end-to-end to build a larger number strip and then lay that large strip out on the floor, demonstrating joining equal-length strips in a contiguous sequence.

Students lay out craft sticks in a neat row to show specific numbers (4, 9, 16, 24) and are instructed to group every fifth stick diagonally to form groups of five. Students practice counting the sticks by 5s and then adding remaining units, and they draw tally marks to copy the stick arrangements. Students also line Skittles up next to one another to compare quantities.

Students are given colored one-inch squares (from Lesson 3) and asked to place and glue them to form rectangular bars that reach the correct numbers on a vertical scale (e.g., "the bar above 'red' should reach the number 5"). In Activity 2 students color a specified number of boxes above each sea creature (e.g., color 7 boxes for 7 eels) so the height of each bar is built from same-size boxes. Optional activities ask students to line Skittles up in rows and align them so they can count differences, reinforcing use of repeated equal items to span a space.

Students draw lines to divide construction paper into 12 one-inch strips and cut those strips, creating same-size length units. Students lay the strips side by side and in order to check that they have the correct number of strips before making paper-chain links. Students build chains that must have specified total numbers of links (for example, 12, 15, 16) and make labels showing the addition sentence that represents the count of links (e.g., 5+5+5=15).

Students are asked to line up 10 unit blocks so they are touching and place a ten rod directly above the row to see that the 10 units form a ten. In Activity 1 and Day 2 students physically show numbers (e.g., 11, 14, 19, 20, 21, 30) by placing unit blocks end-to-end and by using ten rods and the abacus to count groups of ten and individual units. The directions explicitly prompt students to closely line up unit blocks with no gaps when demonstrating that 10 unit blocks equal a ten rod.

Students trade 10 unit blocks for a ten rod and trade 10 ten rods for a hundred flat, showing that 10 tens equals 100. Students are asked to line up all 10 ten rods on top of the hundred flat and see that they fit perfectly, demonstrating that multiple copies of a shorter unit span the larger object. Students group and count 100 small objects in tens (using baggies/plates) and count by tens to show they have 100.

The Skills section lists "Order three objects by length," and Activity 3 has students compare and put shoes in order from shortest to longest. The Wrapping Up activity asks students to put family members' socks in order from shortest to longest and to explain how they determined the order. The Measurement Tools page names rulers and tape measures, exposing students to tools used for length measurement.

Students place their feet heel-to-toe and count how many of their feet span between two marked points (Activity 3). Students lay paper clips end to end, touching but not overlapping, alongside a string and count how many paper clips long the string is (Activity 4). Students record lengths of classroom items in whole units (paper clips or base-10 blocks) on the Lining Up! activity page and place cut string pieces in order from shortest to longest using chosen uniform units.

Activity 2 directs students to choose a unit (ten rod or unit block), line units up end to end and touching, and write how many units span pictured objects. Activity 4 has students place marshmallows in a straight line with no gaps and count the marshmallows to record actual lengths. Activity 3 asks students to identify incorrect measurements (gaps, overlaps, units not aligned with object ends) and to state the rule to lay units end to end with no gaps or overlaps.

Students are shown how to measure a piece of furniture by aligning one craft stick at the bottom and placing additional sticks end-to-end, with explicit instruction to alternate sticks and avoid gaps. The scavenger hunt Student Activity Page asks students to find objects that are exactly the length or width of a specified number of popsicle sticks, paper clips, or ten rods (for example, the length of 8 popsicle sticks). In the long jump/high jump activity, students choose a single measurement unit, line the end of the unit at the starting point, and use it repeatedly to determine how many units their jumps span.

Students are prompted to choose and use a specific unit of measure (for example, a craft stick or ten rod) to determine which cotton ball or straw is tossed the farthest. Students are told to measure the distances of tosses and throws and to record those distances and the chosen unit on provided recording sheets. Day 4 directs students to measure distances during the games and record results, reinforcing practice with measuring lengths.

The Skills section explicitly states that students will "Express the length of an object as a whole number of length units, by laying multiple copies of a shorter object (the length unit) end to end." Activity 1 and the Student Activity Page require students to use a marker as a unit and find objects that are the same length, longer, shorter, and specifically 3, 5, and 7 markers long. The activity asks students to write or draw the objects they find, which requires them to identify and count whole-number multiples of the marker as a unit.